Clinical management decisions for patients with cancer are increasingly being guided by prognostic and predictive markers. Use of these markers should be based on a sufficiently comprehensive body of unbiased evidence to establish that benefits to patients outweigh harms and to justify expenditure of health care dollars. Careful assessments of the clinical utility of markers by using comparative effectiveness research methods are urgently needed to more rigorously summarize and evaluate the evidence, but multiple factors have made such assessments difficult. The literature on tumor markers is plagued by nonpublication bias, selective reporting, and incomplete reporting. Several measures to address these problems are discussed, including development of a tumor marker study registry, greater attention to assay analytic performance and specimen quality, use of more rigorous study designs and analysis plans to establish clinical utility, and adherence to higher standards for reporting tumor marker studies. More complete and transparent reporting by adhering to criteria such as BRISQ [Biospecimen Reporting for Improved Study Quality] criteria for reporting details about specimens and REMARK [Reporting Recommendations for Tumor Marker Prognostic Studies] criteria for reporting a multitude of aspects relating to study design, analysis, and results, is essential for reliable assessment of study quality, detection of potential biases, and proper interpretation of study findings. Adopting these measures will improve the quality of the body of evidence available for comparative effectiveness research and enhance the ability to establish the clinical utility of prognostic and predictive tumor markers.
Up to 25% of patients discontinue adjuvant aromatase inhibitor (AI) therapy due to intolerable symptoms. Predictors of which patients will be unable to tolerate these medications have not been defined. We hypothesized that inherited variants in candidate genes are associated with treatment discontinuation because of AI-associated toxicity.
We prospectively evaluated reasons for treatment discontinuation in women with hormone receptor-positive breast cancer initiating adjuvant AI through a multicenter, prospective, randomized clinical trial of exemestane versus letrozole. Using multiple genetic models, we evaluated potential associations between discontinuation of AI therapy because of toxicity and 138 variants in 24 candidate genes, selected a priori, primarily with roles in estrogen metabolism and signaling. To account for multiple comparisons, statistical significance was defined as p<0.00036.
Of the 467 enrolled patients with available germline DNA, 152 (33%) discontinued AI therapy because of toxicity. Using a recessive statistical model, an intronic variant in ESR1 (rs9322336) was associated with increased risk of musculoskeletal toxicity-related exemestane discontinuation (HR 5.0 (95% CI 2.1–11.8), p<0.0002).
An inherited variant potentially affecting estrogen signaling may be associated with exemestane-associated toxicity, which could partially account for intra-patient differences in AI tolerability. Validation of this finding is required.
breast cancer; aromatase inhibitor; single nucleotide polymorphism; treatment discontinuation; toxicity
The aromatase inhibitor anastrozole inhibits estrogen synthesis. Fulvestrant binds and accelerates degradation of estrogen receptors. We hypothesized that these two agents in combination might be more effective than anastrozole alone in patients with hormone-receptor (HR)–positive metastatic breast cancer.
Postmenopausal women with previously untreated metastatic disease were randomly assigned, in a 1:1 ratio, to receive either 1 mg of anastrozole orally every day (group 1), with crossover to fulvestrant alone strongly encouraged if the disease progressed, or anastrozole and fulvestrant in combination (group 2). Patients were stratified according to prior or no prior receipt of adjuvant tamoxifen therapy. Fulvestrant was administered intramuscularly at a dose of 500 mg on day 1 and 250 mg on days 14 and 28 and monthly thereafter. The primary end point was progressionfree survival, with overall survival designated as a prespecified secondary outcome.
The median progression-free survival was 13.5 months in group 1 and 15.0 months in group 2 (hazard ratio for progression or death with combination therapy, 0.80; 95% confidence interval [CI], 0.68 to 0.94; P = 0.007 by the log-rank test). The combination therapy was generally more effective than anastrozole alone in all subgroups, with no significant interactions. Overall survival was also longer with combination therapy (median, 41.3 months in group 1 and 47.7 months in group 2; hazard ratio for death, 0.81; 95% CI, 0.65 to 1.00; P = 0.05 by the log-rank test), despite the fact that 41% of the patients in group 1 crossed over to fulvestrant after progression. Three deaths that were possibly associated with treatment occurred in group 2. The rates of grade 3 to 5 toxic effects did not differ significantly between the two groups.
The combination of anastrozole and fulvestrant was superior to anastrozole alone or sequential anastrozole and fulvestrant for the treatment of HR-positive metastatic breast cancer, despite the use of a dose of fulvestrant that was below the current standard.
Few intervention programs assist patients and their family caregivers to manage advanced cancer and maintain their quality of life (QOL). This study examined: 1) whether patient-caregiver dyads (i.e., pairs) randomly assigned to a Brief or Extensive dyadic intervention (the FOCUS Program) had better outcomes than dyads randomly assigned to usual care, and 2) if patients' risk for distress (RFD) and other factors moderated the effect of the Brief or Extensive Program on outcomes.
Advanced cancer patients and their caregivers (N=484 dyads) were stratified by patients' baseline risk for distress (high versus low), cancer type (lung, colorectal, breast, prostate), and research site, and then randomly assigned to a Brief (3-session) or Extensive (6-session) intervention or Control. The interventions offered dyads information and support. Intermediary outcomes were: appraisals (i.e., appraisal of illness/caregiving, uncertainty, hopelessness) and resources (i.e., coping, interpersonal relationships, and self-efficacy). The primary outcome was QOL. Data were collected prior to intervention and post-intervention (3 and 6 months from baseline). The final sample was 302 dyads. Repeated Measures MANOVA was used to evaluate outcomes.
Significant Group by Time interactions showed there was improvement in dyads' coping (p<.05), self-efficacy (p<.05), and social QOL (p<.01), and in caregivers' emotional QOL (p<.05). Effects varied by intervention dose. Most effects were found at 3 months only. Risk for distress accounted for very few moderation effects.
Both Brief and Extensive programs had positive outcomes for patient-caregiver dyads, but few sustained effects. Patient-caregiver dyads benefit when viewed as the “unit of care.”
Oncology; cancer; randomized clinical trial; family caregiver; advanced cancer; quality of life; intervention dose; risk for distress
Although current breast cancer treatment guidelines limit the use of HER2 blocking agents to tumors with HER2 gene amplification, recent retrospective analyses suggest that a wider group of patients may benefit from this therapy. Utilizing breast cancer cell lines, mouse xenograft models and matched human primary and metastatic tissues, we demonstrate that HER2 is selectively expressed in and regulates self-renewal of the cancer stem cell population in ER+, HER2− luminal breast cancers. Although trastuzumab had no effects on the growth of established luminal breast cancer mouse xenografts, administration after tumor inoculation blocked subsequent tumor growth. HER2 expression is increased in luminal tumors grown in mouse bone xenografts, as well as in bone metastases from breast cancer patients compared to matched primary tumors. Furthermore this increase in HER2 protein expression was not due to gene amplification but rather was mediated by RANK-ligand in the bone microenvironment. These studies suggest that the clinical efficacy of adjuvant trastuzumab may relate to the ability of this agent to target the cancer stem cell population in a process that does not require HER2 gene amplification. Furthermore these studies support a cancer stem cell model in which maximal clinical benefit is achieved when cancer stem cell targeting agents are administered in the adjuvant setting.
Personalized medicine is increasingly being employed across many areas of clinical practice, as genes associated with specific diseases are discovered and targeted therapies are developed. Mobile apps are also beginning to be used in medicine with the aim of providing a personalized approach to disease management. In some areas of medicine, patient-tailored risk prediction and treatment are applied routinely in the clinic, whereas in other fields, more work is required to translate scientific advances into individualized treatment. In this forum article, we asked specialists in oncology, neurology, endocrinology and mobile health technology to discuss where we are in terms of personalized medicine, and address their visions for the future and the challenges that remain in their respective fields.
Diabetes; Genetics; Mobile health; Oncology; Personalized medicine; Smartphone; Stroke; Targeted therapy
Aromatase inhibitors (AIs) are effective for treatment of hormone receptor–positive breast cancer, but adherence and persistence with therapy are poor. Predictors of treatment discontinuation are not clearly defined. It is unknown whether patients with intolerable toxicity from one AI are able to tolerate another.
Patients and Methods
Women with early-stage breast cancer initiating AI therapy were enrolled onto a multicenter, prospective, open-label randomized trial of exemestane versus letrozole. Patients completed symptom questionnaires at baseline and serially during therapy. Patients who developed AI-associated intolerable symptoms and discontinued treatment were given the option to switch to the other study AI after a 2- to 8-week washout period.
Of the 503 enrolled women, 32.4% discontinued initial AI therapy within 2 years because of adverse effects; 24.3% discontinued specifically because of musculoskeletal symptoms. Median time to treatment discontinuation as a result of any symptom was 6.1 months (range, 0.1 to 21.2 months) and was significantly shorter in patients randomly assigned to exemestane (hazard ratio [HR], 1.5; 95% CI, 1.1 to 2.1; P = .02). Younger age and taxane-based chemotherapy were associated with higher likelihood of treatment discontinuation (HR, 1.4; 95% CI, 1.02 to 1.9; P = .04; and HR, 1.9; 95% CI, 1.00 to 3.6; P = .048, respectively). Of the 83 patients who chose to switch to the second AI, 38.6% continued the alternate AI for a median of 13.7 months.
Premature discontinuation of initial AI therapy as a result of symptoms is common, although more than one third of patients may be able to tolerate a different AI medication. Additional research is needed to identify predictive tools and interventions for AI-associated treatment-emergent symptoms.
Effects of aromatase inhibitor (AI) therapy on the plasma lipid profile are not clear. Here the authors describe changes in fasting lipids (total cholesterol, high-density lipoprotein [HDL], low-density lipoprotein [LDL], and triglycerides) before and after 3 months of exemestane or letrozole treatment. HDL was reduced in the entire cohort (P < .001) and in the exemestane group (P < .001) but unchanged in the letrozole group (P = .169). LDL was increased in the entire cohort (P = .005) and in the letrozole group (P = .002) but unchanged in the exemestane group (P = .361). This effect was at least partially attributable to washout of tamoxifen as only patients with prior use of tamoxifen experienced a significant increase in LDL. Baseline HDL was an independent predictor of the change in HDL (r2 = −0.128, P < .001), and prior tamoxifen use was associated with greater increases in LDL (r2 = 0.057, P < .001). Use of lipid-altering medications did not protect against the exemestane-induced drop in HDL or the increase in LDL observed in women with prior use of tamoxifen taking letrozole. In conclusion, AI treatment and/or washout of tamoxifen induced detrimental changes in the lipid profile of postmenopausal women with breast cancer.
exemestane; letrozole; breast cancer; lipid profile; cholesterol
The era of Personalized Medicine implies getting the right treatment to the right patient at the right schedule and dose at the right time. Tumor biomarker tests are keys to accomplishing this goal successfully. However, much of the translational research regarding tumor biomarker tests has been haphazard, often using data and specimen sets of convenience and ignoring many of the principles of the scientific method. In papers published simultaneously in BMC Medicine and Nature, McShane and colleagues have proposed a checklist of criteria that should be followed by investigators planning to conduct prospective clinical trials directed towards generating high levels of evidence to demonstrate whether a tumor biomarker test has clinical utility for a specific context. These criteria were generated in response to a roadmap reported by a committee convened by the U.S. Institute of Medicine for generation of omics-based biomarker tests. Taken together with several other initiatives to increase the rigor of tumor biomarker research, these criteria will increase the perception of value for tumor biomarker test research and application in the clinic.
Please see related article: http://www.biomedcentral.com/1741-7015/11/220.
Tumor biomarker tests; Clinical investigation
Accumulating evidence supports the existence of breast cancer stem cells (BCSCs), which are characterized by their capacity to self-renew and divide indefinitely, and resistance to conventional therapies. The Notch pathway is important for stem cell renewal, and is a potential target for BCSC-directed therapy.
Using human breast tumorgraft studies, we evaluated the impact of gamma secretase inhibitors (GSI) on the BCSC population and the efficacy of combining GSI with docetaxel treatment. The mouse experimental therapy paralleled a concurrent clinical trial in advanced breast cancer patients, designed to determine the maximally tolerated dose of the GSI, MK-0752, administered sequentially with docetaxel, and to evaluate BCSC markers in serial tumor biopsies.
Treatment with GSI reduced BCSCs in MC1 and BMC-2147 tumorgrafts by inhibition of the Notch pathway. GSI enhanced the efficacy of docetaxel in preclinical studies. In the clinical trial, 30 patients with advanced breast cancer were treated with escalating doses of MK-0752 plus docetaxel. Clinically meaningful doses of both drugs were possible, with manageable toxicity and preliminary evidence of efficacy. A decrease in CD44+/CD24−, ALDH+, and MSFE were observed in tumors of patients undergoing serial biopsies.
These preclinical data demonstrate that pharmacological inhibition of the Notch pathway can reduce BCSCs in breast tumorgraft models. The clinical trial demonstrates feasibility of combination GSI and chemotherapy, and together these results encourage further study of Notch pathway inhibitors in combination with chemotherapy in breast cancer.
breast cancer; Phase I clinical trial; cancer stem cells; agents with other mechanisms of action; Notch inhibitors
These NCCN Guidelines Insights highlight the important updates/changes specific to the management of metastatic breast cancer in the 2012 version of the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer. These changes/updates include the issue of retesting of biomarkers (estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2) on recurrent disease, new information regarding first-line combination endocrine therapy for metastatic disease, a new section on monitoring of patients with metastatic disease, and new information on endocrine therapy combined with an mTOR inhibitor as a subsequent therapeutic option.
Although tamoxifen can prevent primary breast cancer, few women use it as a preventive measure. A second option, raloxifene, has recently been approved. The objective of the study was to determine women’s interest in tamoxifen and raloxifene after reading a decision aid describing the risks and benefits of each medication. Women with 5-year risk of breast cancer ≥1.66 from two large health maintenance organizations were randomized to receive a decision aid versus usual care. After reading an on-line decision aid that discussed the risks and benefits of tamoxifen and raloxifene, women completed measures of risk perception, decisional conflict, behavioral intentions and actual behavior related to tamoxifen and raloxifene. 3 months following the intervention, 8.1% of participants had looked for additional information about breast cancer prevention drugs and 1.8% had talked to their doctor about tamoxifen and/or raloxifene. The majority, 54.7%, had decided to not take either drug, 0.5% had started raloxifene, and none had started tamoxifen. Participants were not particularly worried about taking tamoxifen or raloxifene and did not perceive significant benefits from taking these drugs. Over 50% did not perceive a change in their risk of getting breast cancer if they took tamoxifen or raloxifene. After reading a DA about tamoxifen and raloxifene, few women were interested in taking either breast cancer prevention drug.
decision aids; patient education; tamoxifen; raloxifene; breast cancer prevention
Tamoxifen reduces primary breast cancer incidence, yet has serious side effects. To date, few women with increased breast cancer risk have elected to use tamoxifen for chemoprevention. The objective of the study was to determine women’s knowledge of and attitudes toward tamoxifen following exposure to a tailored decision aid (DA).
632 women with a 5-year risk of breast cancer ≥1.66% (Mean=2.56, range=1.7-17.3) were recruited from 2 healthcare organizations. Participants viewed an online DA that informed them about their 5-year risk of breast cancer and presented individually-tailored content depicting the risks/benefits of tamoxifen prophylaxis. Outcome measures included behavioral intentions (to seek additional information about tamoxifen, to talk to a physician about tamoxifen, and to take tamoxifen); knowledge; and perceived risks and benefits of tamoxifen.
After viewing the DA, 29% of participants said they intended to seek more information or talk to their doctor about tamoxifen, and only 6% believed they would take tamoxifen. Knowledge was considerable, with 63% of women answering at least 5 of 6 knowledge questions correctly. Participants were concerned about the risks of tamoxifen and many believed that the benefits of tamoxifen did not outweigh the risks.
This study is the largest to date to test women’s preferences for taking tamoxifen and one of the largest to have tested the impact of a tailored decision aid. After viewing the DA, women demonstrated good understanding of tamoxifen’s risks and benefits, but most were not interested in taking tamoxifen for breast cancer chemoprevention.
decision aids; patient education; tamoxifen; breast cancer prevention
Adjuvant tamoxifen therapy substantially decreases the risk of recurrence and mortality in women with hormone (estrogen and/or progesterone) receptor–positive breast cancer. Previous studies have suggested that metabolic conversion of tamoxifen to endoxifen by cytochrome P450 2D6 (CYP2D6) is required for patient benefit from tamoxifen therapy.
Tumor specimens from a subset of postmenopausal patients with hormone receptor–positive early-stage (stages I, II, and IIIA) breast cancer, who were enrolled in the randomized double-blind Arimidex, Tamoxifen, Alone or in Combination (ATAC) clinical trial, were genotyped for variants in CYP2D6 (N = 1203 patients: anastrozole [trade name: Arimidex] group, n = 615 patients; tamoxifen group, n = 588 patients) and UDP-glucuronosyltransferase-2B7 (UGT2B7), whose gene product inactivates endoxifen (N = 1209 patients; anastrozole group, n = 606 patients; tamoxifen group, n = 603 patients). Genotyping was performed using polymerase chain reaction–based TaqMan assays. Based on the genotypes for CYP2D6, patients were classified as poor metabolizer (PM), intermediate metabolizer (IM), or extensive metabolizer (EM) phenotypes. We evaluated the association of CYP2D6 and UGT2B7 genotype with distant recurrence (primary endpoint) and any recurrence (secondary endpoint) by estimating the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) using Cox proportional hazards models. All statistical tests were two-sided.
After a median follow-up of 10 years, no statistically significant associations were observed between CYP2D6 genotype and recurrence in tamoxifen-treated patients (PM vs EM: HR for distant recurrence = 1.25, 95% CI = 0.55 to 3.15, P = .64; HR for any recurrence = 0.99, 95% CI = 0.48 to 2.08, P = .99). A near-null association was observed between UGT2B7 genotype and recurrence in tamoxifen-treated patients. No associations were observed between CYP2D6 and UGT2B7 genotypes and recurrence in anastrozole-treated patients.
The results do not support the hypothesis that CYP2D6 genotype predicts clinical benefit of adjuvant tamoxifen treatment among postmenopausal breast cancer patients.
A simple oral combination of capecitabine and cyclophosphamide for the treatment of patients with metastatic breast cancer was evaluated. The addition of cyclophosphamide did not result in outcomes superior to those seen with capecitabine alone.
After completing this course, the reader will be able to:
Compare outcomes in patients treated with capecitabine plus CPA with those of capecitabine monotherapy and combination therapy with bevacizumab, sorafenib, or ixabepilone.Identify patients for whom single-agent capecitabine is recommended.
This article is available for continuing medical education credit at CME.TheOncologist.com
Interest in oral agents for the treatment of metastatic breast cancer (MBC) has increased because many patients prefer oral to i.v. regimens. We evaluated a simple oral combination of capecitabine with cyclophosphamide (CPA) for MBC.
The trial was designed to determine whether or not combination therapy would achieve a 42% response rate (RR) using the Response Evaluation Criteria in Solid Tumors (RECIST) in MBC. Patients with two or fewer prior chemotherapy regimens for MBC were eligible. Those with estrogen receptor–positive MBC had to have progressed on endocrine therapy. Patients had measurable disease or elevated mucin (MUC)-1 antigen and received CPA, 100 mg daily on days 1–14, and capecitabine, 1,500 mg twice daily on days 8–21, in 21-day cycles.
In 96 eligible patients, the median progression-free survival (PFS) interval was 5.9 months (95% confidence interval [CI], 3.7–8.0 months) and median overall survival (OS) time was 18.8 months (95% CI, 13.1–22.0 months). The RR was 36% (95% CI, 26%–48%) in 80 patients with measurable disease. The MUC-1 antigen RR was 33% (95% CI, 20%–48%), occurring in 15 of 46 patients with elevated MUC-1 antigen. Toxicity was mild, with no treatment-related deaths.
PFS, OS, and RR outcomes with capecitabine plus CPA compare favorably with those of capecitabine monotherapy and combination therapy with bevacizumab, sorafenib, or ixabepilone. The addition of these other agents to capecitabine does not improve OS time in MBC patients, and this single-arm study does not suggest that the addition of CPA to capecitabine has this potential in an unselected MBC population. When OS prolongation is the goal, clinicians should choose single-agent capecitabine.
Metastatic breast cancer; Capecitabine; Cyclophosphamide; Oral therapy
Imatinib mesylate is a potent inhibitor of the Bcr-Abl, c-kit, and platelet-derived growth factor receptor (PDGFR) tyrosine kinases. Based on variable expression of c-kit and PDGFR in breast cancer, and on in vitro data supporting synergy between imatinib and capecitabine, the Southwest Oncology Group conducted a phase II trial of the combination in metastatic breast cancer.
Patients and Methods
Eligible patients had progressive, measurable metastatic breast cancer and received up to two prior chemotherapy regimens for metastatic disease. Prior 5-fluorouracil or capecitabine for metastatic disease was not allowed. Patients were accrued on a 2-stage design and received imatinib mesylate 400 mg by mouth daily and capecitabine at 1000 mg/m2 by mouth twice daily for 14 days of a 21-day cycle. The primary endpoint was the confirmed response rate (RR). Tumors were evaluated for c-kit, PDGFRβ, and hormone receptor expression.
Nineteen fully evaluable patients were enrolled with a confirmed RR of 11% (95% CI 1–33%). Eleven percent had unconfirmed partial responses and 42% had stable disease. The trial did not accrue to the second stage. The estimated 6-month progression-free survival was 16% (95% CI 0–32%) and the median overall survival was 14 months (95% CI 7–15). The combination was well tolerated. Of 8 available tumor samples, 2 stained for c-kit and all had stromal staining for PDGFRβ.
In unselected patients, the combination of imatinib mesylate and capecitabine was well tolerated but did not result in improved response rates compared to that reported with capecitabine alone.
breast cancer; imatinib mesylate; capecitabine
Uncontrolled proliferation is a hallmark of cancer. In breast cancer, immunohistochemical assessment of the proportion of cells staining for the nuclear antigen Ki67 has become the most widely used method for comparing proliferation between tumor samples. Potential uses include prognosis, prediction of relative responsiveness or resistance to chemotherapy or endocrine therapy, estimation of residual risk in patients on standard therapy and as a dynamic biomarker of treatment efficacy in samples taken before, during, and after neoadjuvant therapy, particularly neoadjuvant endocrine therapy. Increasingly, Ki67 is measured in these scenarios for clinical research, including as a primary efficacy endpoint for clinical trials, and sometimes for clinical management. At present, the enormous variation in analytical practice markedly limits the value of Ki67 in each of these contexts. On March 12, 2010, an international panel of investigators with substantial expertise in the assessment of Ki67 and in the development of biomarker guidelines was convened in London by the cochairs of the Breast International Group and North American Breast Cancer Group Biomarker Working Party to consider evidence for potential applications. Comprehensive recommendations on preanalytical and analytical assessment, and interpretation and scoring of Ki67 were formulated based on current evidence. These recommendations are geared toward achieving a harmonized methodology, create greater between-laboratory and between-study comparability, and allow earlier valid applications of this marker in clinical practice.
In 2004, circulating tumor cells (CTC) enumeration by the CellSearch® technique at baseline and during treatment was reported to be associated with prognosis in metastatic breast cancer patients. In 2008, the first evidence of the impact of CTC detection by this technique on survival of cM0(i+) patients were reported. These findings were confirmed by other non-interventional studies, whereas CTC were also investigated as a surrogate for tumor biology, mainly for HER2 expression/amplification. The aim of this report is to present the current prospective large interventional studies that have been specifically designed to demonstrate that CTC enumeration/characterization may improve the management of breast cancer patients: STIC CTC METABREAST (France) and Endocrine Therapy Index (USA) assess the CTC-guided hormone therapy vs chemotherapy decision in M1 patients; SWOG0500 (USA) and CirCe01 (France) assess the CTC count changes during treatment in metastatic patients; DETECT III (M1 patients, Germany) and Treat CTC (cM0(i+) patients, European Organization for Research and Treatment of Cancer/Breast International Group) assess the use of anti-HER2 treatments in HER2-negative breast cancer patients selected on the basis of CTC detection/characterization. These trials have different designs in various patient populations but are expected to be the pivotal trials for CTC implementation in the routine management of breast cancer patients.
Breast cancer; CellSearch®; Circulating tumor cells
The authors conclude that intravaginal estradiol treatment, regardless of type, results in elevated circulating E2 levels in this population and should be used with caution.
Intravaginal estradiols (VE) have been proposed as safe alternatives to systemic estrogen therapy in breast cancer survivors.
Patients and Methods:
Postmenopausal women with estrogen receptor–positive breast cancer or at high risk for breast cancer (n = 24) who were taking an aromatase inhibitor (AI) or a selective estrogen receptor modulator (SERM) and VE for ≥ 90 days for atrophic vaginitis and 24 controls taking AI only participated in the study. Serum samples were drawn from VE ring patients before insertion and 30 and 60 days postinsertion, from VE tablet patients the morning before insertion and approximately 12 hours postinsertion, and once from controls. Samples were assayed for E2 concentrations by using highly sensitive radioimmunoassay after ether extraction.
Mean E2 levels in controls were 3.72 pmol/L (range, < 3.0-7.7 pmol/L); mean E2 levels preinsertion and 12 weeks postinsertion in the VE ring patients were significantly greater than controls (P < .001 for each comparison). Mean preinsertion E2 levels in patients using VE tablets were not significantly different than those of controls (P = .48), and postinsertion levels were 76 pmol/L higher than preinsertion (P < .001).
VE treatment increased E2 levels. Preinsertion levels for patients receiving VE tablets were not elevated compared with those of controls, suggesting that E2 elevations with this preparation may not be continuously sustained. We conclude that VE treatment, regardless of type, results in elevated circulating E2 levels in this population and should be used with caution.
This manuscript summarizes current thinking on the value and promise of evolving circulating tumor cell (CTC) technologies for cancer patient diagnosis, prognosis, and response to therapy, as well as accelerating oncologic drug development. Moving forward requires the application of the classic steps in biomarker development–analytical and clinical validation and clinical qualification for specific contexts of use. To that end, this review describes methods for interactive comparisons of proprietary new technologies, clinical trial designs, a clinical validation qualification strategy, and an approach for effectively carrying out this work through a public-private partnership that includes test developers, drug developers, clinical trialists, the US Food & Drug Administration (FDA) and the US National Cancer Institute (NCI).
Circulating tumor cells; Prognostic biomarker; Predictive biomarker; Analytical validation; Clinical validation; Biomarker qualification; Oncologic drug development
Human biospecimens are subject to a number of different collection, processing, and storage factors that can significantly alter their molecular composition and consistency. These biospecimen preanalytical factors, in turn, influence experimental outcomes and the ability to reproduce scientific results. Currently, the extent and type of information specific to the biospecimen preanalytical conditions reported in scientific publications and regulatory submissions varies widely. To improve the quality of research utilizing human tissues, it is critical that information regarding the handling of biospecimens be reported in a thorough, accurate, and standardized manner. The Biospecimen Reporting for Improved Study Quality recommendations outlined herein are intended to apply to any study in which human biospecimens are used. The purpose of reporting these details is to supply others, from researchers to regulators, with more consistent and standardized information to better evaluate, interpret, compare, and reproduce the experimental results. The Biospecimen Reporting for Improved Study Quality guidelines are proposed as an important and timely resource tool to strengthen communication and publications around biospecimen-related research and help reassure patient contributors and the advocacy community that the contributions are valued and respected.
Whole genome amplification (WGA) technologies can be used to amplify genomic DNA when only small amounts of DNA are available. The Multiple Displacement Amplification Phi polymerase based amplification has been shown to accurately amplify DNA for a variety of genotyping assays; however, it has not been tested for genotyping many of the clinically relevant genes important for pharmacogenetic studies, such as the cytochrome P450 genes, that are typically difficult to genotype due to multiple pseudogenes, copy number variations, and high similarity to other related genes. We evaluated whole genome amplified samples for Taqman™ genotyping of SNPs in a variety of pharmacogenetic genes. In 24 DNA samples from the Coriell human diversity panel, the call rates, and concordance between amplified (∼200-fold amplification) and unamplified samples was 100% for two SNPs in CYP2D6 and one in ESR1. In samples from a breast cancer clinical trial (Trial 1), we compared the genotyping results in samples before and after WGA for three SNPs in CYP2D6, one SNP in CYP2C19, one SNP in CYP19A1, two SNPs in ESR1, and two SNPs in ESR2. The concordance rates were all >97%. Finally, we compared the allele frequencies of 143 SNPs determined in Trial 1 (whole genome amplified DNA) to the allele frequencies determined in unamplified DNA samples from a separate trial (Trial 2) that enrolled a similar population. The call rates and allele frequencies between the two trials were 98 and 99.7%, respectively. We conclude that the whole genome amplified DNA is suitable for Taqman™ genotyping for a wide variety of pharmacogenetically relevant SNPs.
whole genome amplification; pharmacogenetics; genotyping; CYP
Weight gain is an important concern that impacts on breast cancer outcomes and general health in survivorship. This randomized, pilot study evaluated whether or not women could comply with a weight control program that is initiated at the beginning of chemotherapy for breast cancer. The program sought to prevent weight gain using a low-fat, high fruit-vegetable diet combined with moderate physical activity. The intervention was implemented using a telephone counseling approach that blended motivational interviewing with social cognitive theory. A total of 40 women were recruited over 9 months at the University of Michigan Comprehensive Cancer Center. This represents 55% of eligible women referred to the study and indicates that interest in a healthy lifestyle program at the initiation of chemotherapy for breast cancer was high. Subjects who dropped out had significantly lower fruit and vegetable intakes and lower blood carotenoids at baseline than subjects who completed the study. Statistically significant beneficial effects were observed on fruit and vegetable intakes, physical activity and breast cancer-specific well-being by the intervention. Mean body fat from dual energy X-ray absorptiometry increased in the written materials arm and decreased in the intervention arm. Of the enrolled women, 75% completed 12 months on study and satisfaction with study participation was high. These data indicate that lifestyle intervention during breast cancer treatment is feasible during treatment with chemotherapy for breast cancer and benefits women in several domains.
obesity; breast cancer; diet; physical activity; weight gain